diff --git a/PKHeX.Core/Legality/Areas/EncounterArea.cs b/PKHeX.Core/Legality/Areas/EncounterArea.cs
index 1f237acab..d55490896 100644
--- a/PKHeX.Core/Legality/Areas/EncounterArea.cs
+++ b/PKHeX.Core/Legality/Areas/EncounterArea.cs
@@ -9,8 +9,8 @@ namespace PKHeX.Core
     public abstract class EncounterArea : IVersion
     {
         public GameVersion Version { get; }
-        public int Location { get; protected set; }
-        public SlotType Type { get; protected set; } = SlotType.Any;
+        public int Location { get; protected init; }
+        public SlotType Type { get; protected init; } = SlotType.Any;
         public EncounterSlot[] Slots = Array.Empty<EncounterSlot>();
 
         protected EncounterArea(GameVersion game) => Version = game;
diff --git a/PKHeX.Core/Legality/Encounters/EncounterSlot/EncounterSlot.cs b/PKHeX.Core/Legality/Encounters/EncounterSlot/EncounterSlot.cs
index 9a62e7513..6039f6388 100644
--- a/PKHeX.Core/Legality/Encounters/EncounterSlot/EncounterSlot.cs
+++ b/PKHeX.Core/Legality/Encounters/EncounterSlot/EncounterSlot.cs
@@ -8,10 +8,10 @@ namespace PKHeX.Core
     /// <remarks>Wild encounter slots are found as random encounters in-game.</remarks>
     public abstract class EncounterSlot : IEncounterable, ILocation
     {
-        public int Species { get; protected set; }
-        public int Form { get; protected set; }
-        public int LevelMin { get; protected set; }
-        public int LevelMax { get; protected set; }
+        public int Species { get; protected init; }
+        public int Form { get; protected init; }
+        public int LevelMin { get; protected init; }
+        public int LevelMax { get; protected init; }
         public abstract int Generation { get; }
         public bool EggEncounter => false;
         public override string ToString() => $"{(Species) Species} @ {LevelMin}-{LevelMax}";
diff --git a/PKHeX.Core/Legality/Encounters/EncounterSlot/EncounterSlot6XY.cs b/PKHeX.Core/Legality/Encounters/EncounterSlot/EncounterSlot6XY.cs
index 4fcb17e81..02213bc83 100644
--- a/PKHeX.Core/Legality/Encounters/EncounterSlot/EncounterSlot6XY.cs
+++ b/PKHeX.Core/Legality/Encounters/EncounterSlot/EncounterSlot6XY.cs
@@ -7,7 +7,7 @@ namespace PKHeX.Core
     public sealed class EncounterSlot6XY : EncounterSlot
     {
         public override int Generation => 6;
-        public bool Pressure { get; set; }
+        public bool Pressure { get; init; }
 
         public EncounterSlot6XY(EncounterArea6XY area, int species, int form, int min, int max) : base(area)
         {
@@ -31,10 +31,7 @@ public override string GetConditionString(out bool valid)
 
         public EncounterSlot6XY CreatePressureFormCopy(int evoForm)
         {
-            var clone = (EncounterSlot6XY)Clone();
-            clone.Form = evoForm;
-            clone.Pressure = true;
-            return clone;
+            return new((EncounterArea6XY) Area, Species, evoForm, LevelMin, LevelMax) {Pressure = true};
         }
     }
 }
diff --git a/PKHeX.Core/Legality/Encounters/EncounterStatic/EncounterStatic.cs b/PKHeX.Core/Legality/Encounters/EncounterStatic/EncounterStatic.cs
index ba4a2c67c..da617848d 100644
--- a/PKHeX.Core/Legality/Encounters/EncounterStatic/EncounterStatic.cs
+++ b/PKHeX.Core/Legality/Encounters/EncounterStatic/EncounterStatic.cs
@@ -11,32 +11,32 @@ namespace PKHeX.Core
     /// </remarks>
     public abstract class EncounterStatic : IEncounterable, IMoveset, ILocation, IVersionSet
     {
-        public int Species { get; set; }
-        public int Form { get; set; }
-        public virtual int Level { get; set; }
+        public int Species { get; init; }
+        public int Form { get; init; }
+        public virtual int Level { get; init; }
         public virtual int LevelMin => Level;
         public virtual int LevelMax => Level;
         public abstract int Generation { get; }
         public GameVersion Version { get; set; } = GameVersion.Any;
 
-        public virtual int Location { get; set; }
-        public int Ability { get; set; }
-        public Shiny Shiny { get; set; } = Shiny.Random;
-        public int Gender { get; set; } = -1;
-        public int EggLocation { get; set; }
-        public Nature Nature { get; set; } = Nature.Random;
-        public bool Gift { get; set; }
-        public int Ball { get; set; } = 4; // Only checked when is Gift
+        public virtual int Location { get; init; }
+        public int Ability { get; init; }
+        public Shiny Shiny { get; init; } = Shiny.Random;
+        public int Gender { get; init; } = -1;
+        public int EggLocation { get; init; }
+        public Nature Nature { get; init; } = Nature.Random;
+        public bool Gift { get; init; }
+        public int Ball { get; init; } = 4; // Only checked when is Gift
 
-        public IReadOnlyList<int> Moves { get; set; } = Array.Empty<int>();
-        public IReadOnlyList<int> IVs { get; set; } = Array.Empty<int>();
-        public int FlawlessIVCount { get; set; }
+        public IReadOnlyList<int> Moves { get; init; } = Array.Empty<int>();
+        public IReadOnlyList<int> IVs { get; init; } = Array.Empty<int>();
+        public int FlawlessIVCount { get; init; }
 
-        public int HeldItem { get; set; }
-        public int EggCycles { get; set; }
+        public int HeldItem { get; init; }
+        public int EggCycles { get; init; }
 
-        public bool Fateful { get; set; }
-        public bool SkipFormCheck { get; set; }
+        public bool Fateful { get; init; }
+        public bool SkipFormCheck { get; init; }
         public bool EggEncounter => EggLocation > 0;
 
         internal EncounterStatic Clone() => (EncounterStatic)MemberwiseClone();
diff --git a/PKHeX.Core/Legality/Encounters/EncounterStatic/EncounterStatic2.cs b/PKHeX.Core/Legality/Encounters/EncounterStatic/EncounterStatic2.cs
index 1299e2404..55c6d91e2 100644
--- a/PKHeX.Core/Legality/Encounters/EncounterStatic/EncounterStatic2.cs
+++ b/PKHeX.Core/Legality/Encounters/EncounterStatic/EncounterStatic2.cs
@@ -10,7 +10,7 @@ namespace PKHeX.Core
     public class EncounterStatic2 : EncounterStatic
     {
         public sealed override int Generation => 2;
-        public sealed override int Level { get; set; }
+        public sealed override int Level { get; init; }
 
         public EncounterStatic2(int species, int level, GameVersion ver)
         {
diff --git a/PKHeX.Core/Legality/Encounters/EncounterStatic/EncounterStatic8N.cs b/PKHeX.Core/Legality/Encounters/EncounterStatic/EncounterStatic8N.cs
index 8de230d04..3ee55e98d 100644
--- a/PKHeX.Core/Legality/Encounters/EncounterStatic/EncounterStatic8N.cs
+++ b/PKHeX.Core/Legality/Encounters/EncounterStatic/EncounterStatic8N.cs
@@ -16,8 +16,8 @@ public sealed class EncounterStatic8N : EncounterStatic8Nest<EncounterStatic8N>
 
         private IReadOnlyList<byte> NestLocations => Encounters8Nest.NestLocations[NestID];
 
-        public override int Location { get => SharedNest; set { } }
-        public override int Level { get => LevelMin; set { } }
+        public override int Location { get => SharedNest; init { } }
+        public override int Level { get => LevelMin; init { } }
         public override int LevelMin => LevelCaps[MinRank * 2];
         public override int LevelMax => LevelCaps[(MaxRank * 2) + 1];
 
diff --git a/PKHeX.Core/Legality/Encounters/EncounterStatic/EncounterStatic8NC.cs b/PKHeX.Core/Legality/Encounters/EncounterStatic/EncounterStatic8NC.cs
index dd194e093..7a178639f 100644
--- a/PKHeX.Core/Legality/Encounters/EncounterStatic/EncounterStatic8NC.cs
+++ b/PKHeX.Core/Legality/Encounters/EncounterStatic/EncounterStatic8NC.cs
@@ -8,7 +8,7 @@ namespace PKHeX.Core
     /// <inheritdoc cref="EncounterStatic8Nest{T}"/>
     public sealed class EncounterStatic8NC : EncounterStatic8Nest<EncounterStatic8NC>
     {
-        public override int Location { get => SharedNest; set { } }
+        public override int Location { get => SharedNest; init { } }
 
         protected override bool IsMatchLocation(PKM pkm)
         {
diff --git a/PKHeX.Core/Legality/Encounters/EncounterStatic/EncounterStatic8Nest.cs b/PKHeX.Core/Legality/Encounters/EncounterStatic/EncounterStatic8Nest.cs
index ed04800d0..9494a0860 100644
--- a/PKHeX.Core/Legality/Encounters/EncounterStatic/EncounterStatic8Nest.cs
+++ b/PKHeX.Core/Legality/Encounters/EncounterStatic/EncounterStatic8Nest.cs
@@ -15,7 +15,7 @@ public abstract class EncounterStatic8Nest<T> : EncounterStatic, IGigantamax, ID
 
         public bool CanGigantamax { get; set; }
         public byte DynamaxLevel { get; set; }
-        public override int Location { get => SharedNest; set { } }
+        public override int Location { get => SharedNest; init { } }
 
         protected override bool IsMatchLevel(PKM pkm, DexLevel evo)
         {
diff --git a/PKHeX.Core/Legality/Encounters/EncounterStatic/EncounterStatic8S.cs b/PKHeX.Core/Legality/Encounters/EncounterStatic/EncounterStatic8S.cs
index 95a3b045a..5fe8b4318 100644
--- a/PKHeX.Core/Legality/Encounters/EncounterStatic/EncounterStatic8S.cs
+++ b/PKHeX.Core/Legality/Encounters/EncounterStatic/EncounterStatic8S.cs
@@ -10,8 +10,8 @@ namespace PKHeX.Core
     /// <inheritdoc cref="EncounterStatic"/>
     public sealed class EncounterStatic8S : EncounterStatic8
     {
-        public override int Location { get => Locations[0]; set { } }
-        public IReadOnlyList<int> Locations { get; internal set; } = Array.Empty<int>();
+        public override int Location { get => Locations[0]; init { } }
+        public IReadOnlyList<int> Locations { get; init; } = Array.Empty<int>();
         protected override bool IsMatchLocation(PKM pkm) => Locations.Contains(pkm.Met_Location);
     }
 }
\ No newline at end of file
diff --git a/PKHeX.Core/Legality/Encounters/EncounterStatic/EncounterStatic8U.cs b/PKHeX.Core/Legality/Encounters/EncounterStatic/EncounterStatic8U.cs
index cc5521149..e1b271bf5 100644
--- a/PKHeX.Core/Legality/Encounters/EncounterStatic/EncounterStatic8U.cs
+++ b/PKHeX.Core/Legality/Encounters/EncounterStatic/EncounterStatic8U.cs
@@ -8,7 +8,7 @@ namespace PKHeX.Core
     /// <inheritdoc cref="EncounterStatic8Nest{T}"/>
     public sealed class EncounterStatic8U : EncounterStatic8Nest<EncounterStatic8U>
     {
-        public override int Location { get => MaxLair; set { } }
+        public override int Location { get => MaxLair; init { } }
 
         public EncounterStatic8U(int species, int form, int level)
         {
diff --git a/PKHeX.Core/Legality/Encounters/EncounterStatic/EncounterStaticTyped.cs b/PKHeX.Core/Legality/Encounters/EncounterStatic/EncounterStaticTyped.cs
index 6af14b6bb..096ce4f5c 100644
--- a/PKHeX.Core/Legality/Encounters/EncounterStatic/EncounterStaticTyped.cs
+++ b/PKHeX.Core/Legality/Encounters/EncounterStatic/EncounterStaticTyped.cs
@@ -9,12 +9,12 @@ namespace PKHeX.Core
     /// <inheritdoc cref="EncounterStatic"/>
     public sealed class EncounterStaticTyped : EncounterStatic4, IEncounterTypeTile
     {
-        public bool Roaming { get; set; }
+        public bool Roaming { get; init; }
 
         /// <summary>
         /// <see cref="PK4.EncounterType"/> values permitted for the encounter.
         /// </summary>
-        public EncounterType TypeEncounter { get; internal set; } = EncounterType.None;
+        public EncounterType TypeEncounter { get; init; } = EncounterType.None;
 
         protected override bool IsMatchLocation(PKM pkm)
         {
diff --git a/PKHeX.Core/Legality/Encounters/EncounterTrade/EncounterTrade.cs b/PKHeX.Core/Legality/Encounters/EncounterTrade/EncounterTrade.cs
index c59977748..460c27981 100644
--- a/PKHeX.Core/Legality/Encounters/EncounterTrade/EncounterTrade.cs
+++ b/PKHeX.Core/Legality/Encounters/EncounterTrade/EncounterTrade.cs
@@ -12,33 +12,33 @@ namespace PKHeX.Core
     /// </remarks>
     public abstract class EncounterTrade : IEncounterable, IMoveset, ILocation, IVersionSet
     {
-        public int Species { get; set; }
-        public int Form { get; set; }
-        public int Level { get; set; }
+        public int Species { get; init; }
+        public int Form { get; init; }
+        public int Level { get; init; }
         public virtual int LevelMin => Level;
         public int LevelMax => 100;
-        public IReadOnlyList<int> Moves { get; set; } = Array.Empty<int>();
+        public IReadOnlyList<int> Moves { get; init; } = Array.Empty<int>();
         public abstract int Generation { get; }
 
-        public int CurrentLevel { get; set; } = -1;
-        public int Location { get; set; }
-        public int Ability { get; set; }
-        public int Gender { get; set; } = -1;
+        public int CurrentLevel { get; init; } = -1;
+        public int Location { get; init; }
+        public int Ability { get; init; }
+        public int Gender { get; init; } = -1;
         public Nature Nature = Nature.Random;
-        public virtual Shiny Shiny { get; set; } = Shiny.Never;
-        public int Ball { get; set; } = 4;
+        public Shiny Shiny { get; init; } = Shiny.Never;
+        public int Ball { get; init; } = 4;
 
-        public int TID { get; set; }
-        public int SID { get; set; }
-        public int OTGender { get; set; } = -1;
+        public int TID { get; internal set; }
+        public int SID { get; internal set; }
+        public int OTGender { get; init; } = -1;
         public GameVersion Version { get; set; } = GameVersion.Any;
 
-        public IReadOnlyList<int> IVs { get; set; } = Array.Empty<int>();
-        public int FlawlessIVCount { get; set; }
+        public IReadOnlyList<int> IVs { get; init; } = Array.Empty<int>();
+        public int FlawlessIVCount { get; init; }
 
         public bool EggEncounter => false;
-        public int EggLocation { get; set; }
-        public bool EvolveOnTrade { get; set; }
+        public int EggLocation { get; init; }
+        public bool EvolveOnTrade { get; init; }
 
         public int TID7
         {
@@ -52,7 +52,7 @@ public int TID7
         private const string _name = "In-game Trade";
         public string Name => _name;
         public string LongName => _name;
-        public bool IsNicknamed { get; set; } = true;
+        public bool IsNicknamed { get; init; } = true;
 
         public IReadOnlyList<string> Nicknames { get; internal set; } = Array.Empty<string>();
         public IReadOnlyList<string> TrainerNames { get; internal set; } = Array.Empty<string>();